383LQ4SS

iTrader: (33)

With some of the things I have seen lately and other guyes like White's testing on nozzle placement....it seems there are more issues with placing the nozzle farther away from the maf on avg than closer. generally from what i have seen lately...the farther away from the MAF the leaner the AF ratio. I have seen a few lean cars lately...and all where corected by changing nozzle location....or nozzle type.

Its not really distance...its more of a volume thing IMO. The volume of the tube or lid you are spraying the dry shot into.

I have gotten some nozzles pretty damn close on dry shots lately and evertime they just go richer.

Not to say that if you got too close...you couldnt spray nitrous right thorugh the MAf without it hardly being seen...but youd have to be like an inch or to away. Nozzle type and spray pattern have an effect too.

Anyways...just an FYI...any of you guys that have lean issues with a dry...put it closer and see what happens.

Sport Side

iTrader: (6)

So bigger tube... More room for the nitrous to go 'unseen' by the MAF. Is that pretty much what you were getting at here?

Kinda going back to what White2001S10 used to talk about... If I spray 2-3'' away at the MAF directly, am I going to freeze it?

I used a ZEX cone filter which directs the nitrous directly down stream but, I placed the MAF 9'' away from its entrance. This STILL froze it. I don't know if I should go to a nozzle setup or push the MAF further away.

So, I guess I'm saying... How can we get a good rich mixture but not freeze the MAF?

383LQ4SS

iTrader: (33)

I dont think the its "unseen" as far as not getting a good spray and crossection of nitrous going across the wires...I think its "unseen" because the nitrous dissapates to more of a gas. if you have ever had yuor hand sprayed at close proximity its almost as if there are large droplets or particles of nitrous that come flying out...they STING as they hit your skin. if you do the same thing a little farther away its not so bad...just very cold. I think its more of a direct contact of the much more dense liquid nitrous actually touching the MAF wires at it flys past and having a much greater impact on reporting. It doesnt take nitrous long once in the atmosphere to begin shifting back to gas. I think the more it gets back to gas as it flows past the maf the less is reported...even though its the same overall MASS.


The only reason i brough this up is because i have seen a few people with dry kits have issues lately. And they all were fixed with placing the nozzle or nitrous outlet point closer to the MAf resulting in less volume before the MAF.

That and what White has done has pretty much convinced me the you could tune your Af ratio with nozzle placement. On an intake like mine where its a straight tube i bet I could change the AF simply by moving the nozzle closer or farther.. Currently my Af on the dry is 10.5 to 1. I think Im gonna move it out about 5 inches and see how that does.

Sport Side

iTrader: (6)

Just to clarify for my sake, do you have the nozzle pointed towards the MAF or facing against the vacuum/flow of air?

So perhaps if you had the nozzle placed 1'' away from the MAF but faced against the flow.... Would this reduce the chances of icing it over but still get a strong reading across the wires to get a decent A/F?

I'd like to see a clear lid setup with the motor on a dyno and the nozzle facing opposite flow. Just to see what happens to the nitrous as vacuum pulls it the other direction.

383LQ4SS

iTrader: (33)

I am not sure what freeezing is or if that actually happens the way some are thinking. It may reduce the temp to below freezing...but I doubt it looks like the inside of an icebox in humid conditions with 2 inches of frost on it. Even if a small amount of moisute glazed over the wires the result would probably be like what White has seen...MAX output of fuel and very rich.

Keep in mind I have sprayed 300+ all dry within5 inches of the MAF in very humid conditions with no ill effects.

So even if it is "freezing" I dont know thats a bad thing as long as the Af i consistant and where you want it. i would not turn the nozzle against the grain unless that was a last resort.

Sport Side

iTrader: (6)

Here's a nitrous pass I made.
My theory on what happened. The pass before, I must have iced the wires over. The wires warmed back up and the vacuum from the motor bent them. Results in screwed up readings on the next pass ---->

Robert56

iTrader: (2)

Here's a tuning aid for those running dual straight nozzles into the center of air box. What i did was change one nozzle to a 90* and they are about 3inches from maf. Many running this cai run a little lean, this from having nozzles pointing away from, and to far away from maf. what Al is saying is right on and I have tested this out several times, location is key to a good a/f. the 5177 comes with straight nozzles and can be a lean problem, this is why we speced the ND PRO Dry kit with SS 90* nozzles-a better a/f on average.
Here's a pic of quad nozzles with one 90* as an aid to my optimum a/f sought, basically low/mid 11 a/f.

Nozzle placement thread
Robert

Robert56

iTrader: (2)

Isn't your nozzle in the cone filter pretty far from maf? If your really convinced that you have an issue, try the nozzle from NX that is a straight shooter but a fogger type. maybe one of the nx guys will see this and post the pic of nozzle and spray pattern.
Robert

Sport Side

iTrader: (6)

Yeah, it was about 9 inches away.
I'm doin a dry, mafless shot at the track now but, I'd eventually like to go back to a maf + dry setup for the street so, i don't have to go between 2 seperate tunes.

firehawk00

This is excellent information. I'm going to relocate my nozzles (currently on the sides of the air box as indicated for the 5177 kit) and get the 90 degree nozzles. Even though I don't know if my car has a lean A/F ratio, I'd rather have a rich condition for safety purposes.

hondo

iTrader: (2)

I wonder if a 45* nozzle would work out for us 5177 users?Still be able to use the nozzles in the side of the lid, but aim the spray straight into the MAF...hmm

383LQ4SS

iTrader: (33)

the 5177 location was always pretty good for me. I wouldnt relocate unless you know you are leaner than you want to be.

Robert56

iTrader: (2)

I agree on the 5177 nozzle location on stock type air boxes. I have seen many, many work well. the reason being, the two nozzles spraying at each other meet in the middle and create a sort of null area, then turn 90* to the maf which is not that far away. Now with that said, some do have lean issues, and this is where tuning by nozzle placement and style may help. I also think that one should find out what their a/f is before randomly moving nozzles around.
Robert

cablebandit

iTrader: (37)

hmmm...i tune my friendscar.it is a cam/boltons ls1..5177 dry kit with 100rwhp jets...i tuned it for 12.6 a/f...is that too lean?

Robert56

iTrader: (2)

Well, yes/no, it all depends. For me and cam/bolt ons I would look for a little richer. It's mostly what your comfortable with on that size shot. i know many who run in that range, but I am not one of them. Opinions?
Robert

383LQ4SS

iTrader: (33)

I generally like to be closer to 12 to 1 at a power level like that.

at very high HP levels I like to be at 11.3-11.7 to 1 or so.

CAT3

iTrader: (9)

Yeah, that whole 12.x:1 on a higher dry shot rating is really not a great idea, ask my old plugs why I prefer to curve the fueling, richer at initial hit, leaning out slightly til peak tq, and then continue leaning out some to peak hp, which after becomes safely rich again. Just happens to be I forgot to load the tune I had been working on for just such an event.

Al, interesting on nozzle placement vs AF. I would prefer to place the nozzles where they like to work (e.g. on a 5177 Lid sides for F Body) and tune it accordingly.

383LQ4SS

iTrader: (33)

CAT..thats probably preferable...however not all dry users have tuning software.

CAT3

iTrader: (9)

Well thats just plum nutz....not that the tuning software works if you dont load the damn thing anyway

Robert56

iTrader: (2)

...and sometimes placement and tuning software work best...
Robert